1. Field of Invention
The invention relates to umbrellas and more particularly to an improved umbrella that is resistant to inversion from the wind.
2. Description of Related Art
Umbrellas are widely used personal articles. It is often that wind will catch an umbrella user unaware and exert a force against an inner surface of a canopy of the umbrella so as to cause the canopy to invert from its normal operable position to an upwardly convex position.
Windproof umbrellas are thus developed for windy weather. For example, U.S. Pat. No. 4,979,534 discloses a windproof comprising a post having a lower end to be grasped by a user and an opposite upper end; a plurality of ribs extending outwardly in a radial direction from the upper end of the post; a lower canopy secured in covering relation on the ribs, the lower canopy including a plurality of vent holes therethrough; a channel forming member secured to the lower canopy in surrounding relation to each lower vent hole for further preventing entry of water therethrough; an upper canopy positioned over the lower canopy in covering relation to all lower vent holes, the upper canopy including at least one upper vent hole therethrough positioned closer to the free ends of the ribs than the at least one lower vent hole, an outer peripheral edge and a plurality of slits extending inwardly in a radial direction from the outer peripheral edge thereof, each slit being arranged generally in line with one rib, the upper canopy having dimensions less than those of the lower canopy; and elastic fastening straps securing the upper canopy between the upper end of the post and the free ends of the ribs with an elastic tautness.
The patent intents to escape excess wind from the vent holes of the lower canopy to the vent hole of the upper canopy. However, in fact, it is difficult of escaping wind through the space between the lower and upper canopies. The windproof umbrella would not be practical since in often times it inverts from its normal position to an upwardly convex position in rainy, windy weather. Thus, the need for improvement still exists.